Large physical collections, whether LP or CD, have their own issues with organization. Regardless of how you organize them -- composer, artist, conductor, orchestra, subgrenre, whatever -- there are going to be albums that contain tracks that don't fit nicely into your chosen method. For example, I have classical albums with multiple different artists, or composers, or orchestras, etc. "Sampler" albums are a great example of this -- Gypsy Classics anyone? Or under which composer do I file
"Rimsky-Korsakov and Moussorgsky"? There are many more examples in my own collection.
Then you want to play the one piece that you enjoyed a few years ago but can't remember exactly which album it was on. Your only option is pull albums off the shelf until you stumble across the one you want. Tagging a digital library can take a bit of work, but you only have to do it once and then things can be much easier to find in my experience.